Lockheed Martin challenges contract to Raytheon

WASHINGTON (Reuters) - Lockheed Martin Corp on Wednesday said it had filed a formal protest with the U.S. Government Accountability Office challenging the U.S. Air Force's decision to pick Raytheon Co to develop a new long-range radar. "We believe that we offered the most affordable and capable solution for the program and have strong grounds for this protest," said Lockheed spokeswoman Rashi Ratan. Lockheed's move follows a similar protest filed on Tuesday by Northrop Grumman Corp. (Reporting by Andrea Shalan; Editing by Bill Trott)